Apparatus for treating small objects by using rotating drums



Aug. 18,1970 H. OETIKER APPARATUS FOR TREATING SMALL OBJECTS BY'USING ROTATING DRUMS Filed April 7, 1967 FIGI {B 4 w 2 M A 3 INVENTOR HANS OETIKER BY My (9L7 ATTORNEYS United States Patent 3,524,735 APPARATUS FOR TREATING SMALL OBJECTS BY USING ROTATING DRUMS Hans Oetiker, Oberdorfstrasse 21,

' Horgeu, Switzerland Filed Apr. 7, 1967, Ser. No. 629,311 Int. Cl. B24b 31/02 US. Cl. 51-164 4 Claims ABSTRACT OF THE DISCLOSURE An apparatus for treating small objects which comprises a rotating support rotatably mounted by way of bearings on a stationary uright base, a plurality of rotating drums rotatably supported on the rotating base, preferably about approximately vertical axes, by way of bearings, and a drive arrangement for rotating the rotatable support and for rotating also the individual drums about their respective axes of rotation relative to the rotating support so that the objects contained in the drums are subjected to large forces causing improved surface finishing, for example, deburring. The drive of the rotating support may take place from an electric motor, preferably of the variable speed type, by way of a chain and sprocket drive while each drum is individually driven from the stationary base by way of a corresponding chain and sprocket drive. In the alternative, meshing gears may be used to effect the rotating movements of the various parts. The drives are so chosen that the rotating support normally rotates at a higher rotational speed than the rotation of the drums relative to the rotating support.

BACKGROUND OF THE INVENTION The present invention relates to an apparatus for treating small objects with the use of rotating drums which are driven by means of a motor. With such prior art apparatus and installations, the rotating drum is normally arranged so as to be tiltable or pivotal about a horizontal axis. For purposes of filling and emptying, the rotating drum can be pivoted with its opening either pointing upwardly or downwardly. Additionally, the rotating drum can also be brought into an inclined position in these prior art apparatus.

Disadvantageous with such prior art apparatus, however, is the required relatively long treatment time. Depending on the size of the parts, this treatment time may amount to many hours. It has now been discovered that the cleansing and treatment effect is dependent to a very large extent on the mutual abutment forces of the small objects and of the added abrasive materials. Heavier parts abrade with larger mutual abutment forces than lighter ones.

SUMMARY OF THE INVENTION It has now been possible to considerably increase the mutual abutment force of the small objects in that the rotating drum is subjected to an additional circular or rotary movement in relation to its axis and thus the small objects are subjected to an additional acceleration effect, whence it is possible to increase the mutual abutment force by a multiple as compared to the effect of a rotating drum rotating only about a fixed or stationary axis.

Installations are known in the prior art in which the rotating drums are disposed horizontally with the axes of rotation thereof and these axes of rotation additionally carry out circular movements on a cylindrical surface. These rotating drums of the prior art are supported in pivot bearings on both sides. The opening for the filling and emptying of the drum is arranged in the ice cylinder wall. The cover for this opening requires a very reliable and accurate seal. The quality of the seal must be very high because, for example, the liquid which may be filled into the drum, seeks to escape at the sealing places with an apparent multiple Weight or liquid pressure. These disadvantages are eliminated by the present invention.

The invention thereby starts with the basic concept to cause, in addition to the additional accelerating forces acting on the small objects or parts, simultaneously also the force of gravity to act on the small objects or parts in the direction of the axis of rotation whereby, at the outset, additionally an axial additional movement of the parts is obtained during the mixing. The small parts or objects are exposed thereby to three essential force components, on the one hand, to the centrifugal effect, caused by the rotating movement of the drum axis, then the centrifugal effect as a result of rotation of the rotating drum itself and finally the gravity perpendicularly to the centrifugal force effect. The combined effect of these forces leads to a movement of the small objects or parts which produces a particularly effective mixing thereof with simultaneous considerable increase of the apparent Weight and therewith of the abrading pressure.

Accordingly, it is an object of the present invention to provide an apparatus for treating small parts of the type described above which eliminates, by simple means, the aforementioned shortcomings and drawbacks encountered in the prior art constructions.

It is an object of the present invention to provide an apparatus for treating small objects which is simple in construction, relatively inexpensive to manufacture and devoid of requirements for tight and accurate seals of the drums containing the objects.

A still further object of the present invention resides in a treating apparatus of the type described above which results in surprisingly enhanced operating efficiency.

Another object of the present invention resides in a treating apparatus for treating small objects, for example, for deburring or surface finishing such objects, which reduces the time required for treating the objects by a significant factor.

Still a further object of the present invention resides in a treating apparatus which results in better mixing action of the objects within the drum and also in higher abutment pressures, thereby in greater effectiveness.

These and other objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

FIG. 1 is a vertical cross-sectional view through an apparatus in accordance with the present invention; and

FIG. 2 is a plan view on the installation of FIG. 1.

The present invention essentially consists in that two (or more) rotating rotary drums are arranged with their axes at least approximately vertical and symmetrically in relation to the rotation on a rotating support and whose axis is disposed perpendicular to the earths surface.

Referring now to the drawing wherein like reference numerals are used throughout the two views to designate corresponding parts, reference numeral 1 designates therein a vertical or upright base support on which is rotatably arranged the rotating support 2 constituted by two parts 2a and 2b forming a shell, by way of a rotary bearing 3. The rotary bearing 3, in the illustrated embodiment, con sists of two ball bearings, and its axis AA is disposed perpendicularly to the earth surface, i.e. extends normally substantially vertically. Two rotating drums 6 and 7 of any conventional construction are arranged on the rotating support 2 which are rotatably supported in vertical rotary support bearings 4 and 5. The rotating drums 6 and 7 are disposed with their axes B-B parallel and symmetrical to the axis of rotation AA of the rotary bearing 3 of the rotating support 2. The ball bearings of the rotary bearings 4 and are connected with each other by way of a sleeve or bushing 8 and 9, respectively. The sleeves or bushings 8 and 9 are provided with bores into which are adapted to be inserted the rotating drums 6 and 7 by means of the accurately fitting pins 6a and 7a thereof. The drive of the rotating drums 6 and 7 takes place by way of a chain drive, consisting of the sprocket gear wheels 10 and 11 which are rigidly mounted on the stationary base 1 as well as of the sprocket gear wheels 12 and 13 which are non-rotatably mounted on the bushings or sleeves 8 and 9. The driving chains are indicated by reference numeral 14. The drive of the rotating support 2 takes place by means of an adjustable electric motor 15, driving a sprocket gear wheel which is drivingly connected by way of chain 14 with the sprocket gear wheel 19, connected with the rotating support 2 to rotate in unison therewith. The gear wheels 12 and 13 and therewith the rotating drums 6 and 7 are driven synchronously relative to each other and preferably in such a manner that they rotate both in the same direction as the rotating support.

OPERATION Underlying the operation of the installation according to the present invention is the basic concept to expose the filling goods to a centrifugal acceleration which surpasses the acceleration due to gravity by a multiple, i.e., in such a manner that the filling good is subjected to an apparent multiple weight increase. As already mentioned hereinabove, a stronger mutual pressure is to be achieved thereby between the individual pieces whereby the abrading and deburring of the edges takes place more effectively and the operating time is considerably reduced. These accelerating forces act horizontally, i.e., parallelly to the earths surface. However, the filling good is subjected simultaneously also to the acceleration due to gravity which acts in the axial direction of the rotating drum.

As a result of the combined effects of the centrifugal accelerating forces together with the vertically acting force of gravity, a particularly good mixing of the objects or small particles is obtained. These parts, in rough approximation, at first follow an approximately spirally shaped upward movement and thereupon, under the influence of the periodic fluctuations of the centrifugal forces, slide back in spirally shaped paths to the bottom surface of the rotating drums. A considerably improved mixing of the parts results therefrom compared to the known apparatus in which the axes of rotation are disposed horizontally and the gravity cannot act in the direction of the axis of rotation.

The vertical position of the axes of rotation need not be maintained accurately, as deviations from the vertical position are permissive. It suffices if a component of the gravity which is not too small, remains effective in the axial direction so that deviations of about 45 are still permissive. However, such inclined positions require practically a conisderably greater expenditure for the apparatus. Additionally, other means are within the purview of the present invention in order to obtain additional force components in the axial direction of the rotating drums. The parts may be blasted laterally, for example, in horizontally rotating drums. However, all of these means require a considerably greater expenditure than in the case in which the gravity is permitted to act in the axial direction as is the case with the present invention.

The rotating support 2 may, of course, also be provided with more than two rotating drums, for example, with three or four or even more, which permits a better utilization of the installation. These rotating drums are then arranged along a circle and are evenly distributed symmetrically to the axis of rotation AA. However, these drums require a relatively uniform filling of the rotating drums in order to avoid undesirable unbalances.

The drive of the rotating drums may also take place by way of gear wheels which engage in gear wheels mounted on the stationary support 1, such arrangement being readily within the scope of a person skilled in the art and is therefore not illustrated herein. The rotating drums are appropriately provided with a cover. The covers, in turn, are provided with a simple venting aperture in their center in order to prevent a pressure increase on the inside of the drums. There is no danger that the filling liquid escapes through this aperture as the aperture remains free of filling material as a result of the special movement of the filling. As a matter of fact, a cover can be dispensed with altogether and it sufiices to accommodate at the opening of the rotating drum a corresponding inwardly directed rim.

The rotational speed of the rotating support and that of the rotating drums are not dependent directly from each other. Whereas the rotating drums have, as in the prior art installations, a rotational speed of about M to 2 rotations per second, the rotating support 2 rotates considerably more rapidly, for example with about 1 to 10 rotations per second. The average centrifugal acceleration is kept appropriately at 3 to 30 times acceleration due to gravity. With a diameter of the circular path of the rotating drums of about 1 meter, as has been used in practice, the rotational speed of the rotating support amounts to 185 rotations per minute which corresponds to approximately 20 times the acceleration due to gravity. Practical tests have also indicated that with the apparatus of the present invention the time for surface treating objects can be reduced by a factor of about 1/50 accompanied by an increase in the weight of the material removed during this shorter period compared to the weight of material removed heretofore during the corresponding longer treating periods.

While I have shown and described one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to a person skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

I claim:

1. A planetary-type apparatus for treating small objects which includes at least two rotating drum means operable to rotate about their own vertical axes While rotating in unison about a central vertical axis, the drum means being journalled in a rotating support means, and the rotating support means being rotatingly supported on a relatively fixed base support, characterized in that said relatively fixed base support is in the form of an upright member constituting the sole support for said rotating support means and is disposed within the area of said central vertical axis, and in that said rotating support means is formed of .two parts constituting a hollow shell, said two parts being of similar construction and disposed substantially symmetrically to one another, and means for imparting a planetary motion to said drum means including relatively fixed external drive means operatively connected only with said rotating support means and gear drive means located completely within the shell formed by said two parts of said rotating support means for imparting to said drum means the rotary movements about their own axes, said gear drive means including, for each drum means, One gear wheel each operatively connected with a respective drum means and rotatingly supported in the rotating support means by rotary bearing means, on the one hand, and one gear wheel operatively connected with a corresponding first-mentioned gear wheel and fixedly mounted directly on an upright portion of the fixed base support, on the other, and said upright portion extending substantially centrally in the'space formed by said two parts and rotatingly supporting thereon said support means about said central axis.

2. An apparatus according to claim 1, further comprising rotary bearing means for rotatingly supporting said rotating support means on the upright portion of said fixed base support, the axis of said rotating rotary bearing means being disposed essentially perpendicularly to the earths surface, and said rotating support means including at least two rotary bearing means disposed parallelly and symmetrically to the axis of rotation of the r0- tating support means, said rotating drum means being insertable into said two rotary bearing means.

3. An apparatus according to claim 1, wherein said gear drive means is a chain and sprocket-type drive, each of said gear wheels forming a sprocket gear and corresponding sprocket gears bearing drivingly connected by means of chains disposed within said shell-like parts.

4. An apparatus according to claim 1, wherein corresponding gear wheels are in meshing engagement with 20 each other.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 3/ 1956 Great Britain. 9/1965 Germany. 4/1958 U.S.S.R.

OTHER REFERENCES German printed application 1,200,105, September 1965.

HAROLD D. WHITEHEAD, Primary Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE I CERTIFICATE OF CORRECTION Patent No. 3,524,735 August 18, 1970 Hans Oetiker It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, insert Claims priority, application Switzerland, Aprl Signed and sealed this 23rd day of February 1971.

after line 6, 16 1966 (SEAL) Attest: WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, I r.

\ Commissioner of Patents Attesting Officer 

